This is a category D study. Many prescription drugs that are used in the treatment of children have only been studied in adult patients. The purpose of this study is to evaluate the safety profile, efficacy, and pharmacokinetics of etodolac extended-release (ER) in patients with juvenile rheumatoid arthritis. The investigator and the industrial sponsor plan to ensure that etodolac (ER) can be administered in therapeutically relevant doses to children, and to generate appropriate labeling information for this patient population. Etodolac is a non-steroidal anti-inflammatory drug (NSAID), approved in the United States for the management of pain and the management of the signs and symptoms of osteoarthritis and rheumatoid arthritis. The extended-release formulation, developed by Wyeth-Ayerst Research, has a longer duration of action and potentially greater effectiveness and safety than the conventional formulation, as there is less fluctuation in plasma concentrations within a given dosage interval. The drug is administered once daily.